---
task: Create item storage groups (Event/Item, Scan/Time, Aggregation), add items, read history
version: R1.03
source: IM 36K10C40-01EN §2.1, §3, App. 1; IM 36K10L20-01EN §2.1; practiced on CI-Eng-Sample 2026-10-01
status: verified for Event/Item and Scan/Time; Aggregation loads but values not yet seen (ISS-040)
---

# Item storage groups (quick load)

Sample files: `examples/CI-Eng-Sample/03_his_group_df.qli` (groups) and `04_item_his_df.qli`
(items in groups); removal `89_…`, `90a` (generated by `remove.cmd`), `90_…`. Commands as in
skill `system-management` (`dssqld -i` / `-m` / `-r`); `dssqld` exits 0 even on errors — read the
summary table.

## 1. Groups (`HIS_GROUP_DF`)

```
@FIELDS
NAME,DESCRIPTION,TYPE,COL_STOR_TYPE,LIFE_TIME,ROLLOVER_INT
@HIS_GROUP_DF
"<GROUP>","<description>","Item","Event/Item","1 weeks","1 days"

@FIELDS
NAME,DESCRIPTION,TYPE,COL_STOR_TYPE,SCAN_INTERVAL,STORE_QUALITY,LIFE_TIME,ROLLOVER_INT
@HIS_GROUP_DF
"<GROUP>","<description>","Item","Scan/Time",10,1,"1 days","1 hours"

@FIELDS
NAME,DESCRIPTION,TYPE,COL_STOR_TYPE,STORE_QUALITY,LIFE_TIME,ROLLOVER_INT,AGG_PERIOD_HOUR,AGG_PERIOD_30MIN
@HIS_GROUP_DF
"<GROUP>","<description>","Item","Aggregation",1,"4 weeks","1 weeks",1,1
```

- Name ≤ 16 characters. `COL_STOR_TYPE`: `Scan/Time`, `Event/Item`, `Event/Event`,
  `Direct/Event`, `Direct/Item`, `Aggregation`. Other fields: C40 summary §2 (priority, data
  compression, averaging, samples per record, shift/day/week settings, completion item).
- Defaults filled in by the system: first rollover at the next interval boundary, aggregation
  shift 8 h from 00:00, week from Monday.
- Size the life time to the disk: every unit older than the life time is deleted at rollover.

## 2. Items in a group (`ITEM_HIS_DF`)

```
@FIELDS
NAME,ITEM_NAME,GROUP_NAME,ON_VALUE_CHANGE,ON_STATUS_CHANGE
@ITEM_HIS_DF
"<GROUP>:<Section>.<Tag>","<Section>.<Tag>","<GROUP>",1,1

@FIELDS
NAME,ITEM_NAME,GROUP_NAME
@ITEM_HIS_DF
"<SCANGROUP>:<Section>.<Tag>","<Section>.<Tag>","<SCANGROUP>"

@FIELDS
NAME,ITEM_NAME,GROUP_NAME,STORE_AGG_MAX,STORE_AGG_MIN,STORE_AGG_AVG
@ITEM_HIS_DF
"<AGGGROUP>:<Section>.<Tag>","<Section>.<Tag>","<AGGGROUP>",1,1,1
```

Event triggers (`ON_*`) matter for event groups; aggregates (`STORE_AGG_MAX`, `_MIN`, `_AVG`,
`_INTG` + `AGG_INTG_PERIOD`, `_STDV`, `_CNT`, `_DIFF_SUM` + range/percentage) for aggregation
groups. Load the group first; a short pause before linking items avoids a failure seen once
(`load.cmd` waits 5 s).

## 3. Restart

**A new group stores nothing until CI Server is restarted** (verified: groups loaded at 11:32
and 11:54 started storing only after the 12:00 restart). Ask the user to restart the CI Service
(admin) and check the active unit with `history-checks.md`.

## 4. Read history

```
@SELECT
'ITEM_NAME = "<Section>.<Tag>" and GROUP_NAME = "<GROUP>" and SAMPLE_TIME > "<dd-mm-yyyy hh:mm:ss>" and SAMPLE_TIME < "<dd-mm-yyyy hh:mm:ss>"'
@ITEM_HISTORY
```

`dssqld -e <out>.qli <filter>.qli -c`. Item name and a time range are required; times are local.
`GROUP_NAME` picks one group (otherwise every group with the item answers). Columns:
`SAMPLE_TIME`, `SAMPLE_END_TIME`, `INTERVAL_TIME`, `ITEM_VALUE`, `QUALITY`, `INITIAL_VALUE`
(1 = value at unit start), `STATUS`, `INTERPOLATION`, `ATTRIBUTE`, `GROUP_NAME`, …

Aggregates (from docs; **not yet seen on the test system**, ISS-040): add
`and INTERPOLATION = "Hour" and ATTRIBUTE = "Maximum"` (also `Minimum`, `Average`,
`Integration`, `Standard deviation`, `Counter`, `Differential summation`; periods `Hour`, `Day`,
`Month`, `Year`, …). `INTERPOLATION = "Hour"` is accepted by `dssqld`; `"30 minutes"`,
`"30 Minutes"` and `"Half hour"` are refused (`DSSP-E-NOTRANSF … illegal value`), so the
30-minute period name is still unknown.

## 5. Remove

Items first (`ITEM_HIS_DF` names), then give each group a `STOP_TIME` in the future with
`dssqld -m`, wait until it has passed, then `dssqld -r` the groups (an active unit blocks the
delete: `HIS-E-GROUPHASUNT`, ISS-005). `remove.cmd` does this for all three sample groups.
Removing a group deletes its history.

## Verified (CI-Eng-Sample, 2026-10-01)

| Group | Type | Result |
|---|---|---|
| `CIENG_EVENT` | Event/Item, 1 week / 1 day | Live writes stored (12:04:56 = 112); `ithloahis` into active and closed units stored |
| `CIENG_SCAN10S` | Scan/Time 10 s, quality, 1 day / 1 hour | `TANK1.LEVEL` and `INFLOW` every 10 s after the restart |
| `CIENG_AGG` | Aggregation 30 min + hour, 4 weeks / 1 week | Group, items and units created (extra `…zzz…` files); after the restart no 30-minute aggregate was written by 13:00 (ISS-040) |